Refrigerating apparatus



Feb. 11,1941. T. s. WETTER REFRIGERATING APPARATUS Filed Aug. 15, 1958 2Sheets-Sheet '1 INVENTOR Thomas S. weffer ESY M may? ATTORNEYS WITNESSESFeb. '11, 1941. T. s. WETTER 2,231,856

REFRIGERATING APPARATUS Filed Aug. 13, 1938 2. Sheets-Sheet 2 INVENTORThomas S waiter ATTORNEYS WITNESSES Patented Feb. 11, 1941 UNITED STATESPATENT OFFICE V 2,231,856 'REFRIGERATING APPARATUS Thomas S. Wetter, NewYork, N. Y.; Pauline L. Wetter, Kings County, N. Y., administratrix ofThomas S. Wetter, deceased Application August 13, 1938, Serial No.224,719

3 Claims.

This invention relates to refrigerating apparatus and particularly to animproved refrigerating condenser of the evaporator, shower or economizertype.

The increasing use of large size refrigeration machines has caused aproblem for various municipalities due to the large quantities ofcondensing water used. The problem is rapidly approaching an acute stageand is overloading both water supply and sewage systems.

To meet this situation there has been an increasing use of refrigerationcondensers of the type variously known as evaporator, shower, oreconomizer condensers which are combinations of a forced draft watercooling tower and an atmospheric condenser. In this type of condenserthe coil is usually disposed in a housing that has a drip or catch panat the bottom thereof. The water is either sprayed or trickled over thecoil and a fan blows a continuous stream of air through or over thewater and coil. This induces a rapid evaporation of part of the water,cooling the remainder to within several degrees of the wet bulbtemperature of the air. The unevaporated water falls into the drippanand is recirculated by means of a pump. A certain quantity of waterin the system is lost by evaporation and this is compensated for by asupply pipe controlled by a float valve.

The quantities of air and water circulated by the fan and pump may varywidely but it is essential that both fan and motor be in operation inorder for this type of condenser to function. Upon the failure of eitherthe fan or pump the condenser pressure and temperature will mountrapidly reaching the pressure at which the high pressure cutout shutsdown the compressor, or where a fusible plug is employed, reaching thetemperature at which the plug fuses.

It will be appreciated that this interruption of operation caused by thefailure of either or both the pump and condenser is highly undesirableand it is a prime object of this invention to overcome the difficultiesheretofore encountered in this respectand to provide an improvedcondenser which automatically is caused to function as an atmosphericcondenser in case of fan or pump failure.

A further object of the invention is the provision of an improvedcondenser of the economizer, shower or evaporator type which is providedwith an auxiliary water supply which converts the condenser into anatmospheric condenser when the pressure or temperature of the fluid inthe condenser reaches a predetermined level due to failure of the pumpor fan.

Another object is the provision in a condenser of the above character ofmanually operated means in addition to automatically operated meanswhereby the condenser may be caused to function as an atmosphericcondenser.

For a fuller understanding of the invention reference should be had toaccompanying draw- 2, showing one manner in which the thermostatic bulbmay be connected to the condensing coil.

In the accompanying drawings I have illustrated diagrammatically oneform of shower,

economizer, or evaporator condenser to which my invention may be appliedand the apparatus consists generally of a condenser coil 5 having aspray pipe 6 disposed over the top thereof for spraying water on thecoil; a suction fan or a blower for drawing a current of air over thecoil and over and through the water; and a drip pan 8 disposed beneaththe coil for receiving the unevaporated water.

The refrigerant enters the coil 5 at the upper end thereof indicated at9 and circulates through the return bends of the coil where it iscondensed and is then discharged through the outlet lo. As the waterdrips downwardly from the spray pipe 6 the current of air induced by thefan 1 causes rapid evaporation of a certain amount of the water coolingthe remainder of the water and the coil. The unevaporated vwater whichdrips into the pan 8 is recirculated through pipe H by means of pump l2so as to return to the spray pipe 6 where it is again sprayed downwardlyon the coil 5.

In order to compensate for the water lost by evaporation a supply pipeI4 leading from a suit- .able source of water supply (not shown) isconnected to the drip pan 8 and the outlet of the mit more Pipe l4.

water to enter the drip pan through In this way-a substantially uniformquantity of water is maintained in the system at all times.

The mechanism heretofore described forms one standard type ofeconomizer, shower, or evaporator condenser and its construction andoperation will be readily understood by those skilled in the art. Whenthe fan i and pump I2 operate in the proper manner condensers of thistype produce very satisfactory results. However, when either or both thefan or pump cease to function the condenser will no longer operate in asatisfactory manner and the pressure and temperature in the condenserwill rise. In order to cause the continued satisfactory operation of theconsystem for supplying additional water to the condenser coil so thatit may thereafter operate as an atmospheric condenser. The auxiliarysupply preferably takes the form of an additional spray pipe I 8connected by conduit or pipe l9 to pipe 20 which in turn is connected byconduit or pipe 2! to the water supply pipe I4. The flow of waterthrough the pipe 20 is controlled by pressure operated valve 22 andelectrically operated valve 23.

The pipe I9 is also connected by means of a by-pass pipe 24 having amanually controlled valve 25 to the pipe 2!. It will be seen that byopening manually controlled valve 25 water from supply pipe l4 can passthrough pipe 2!, pipe 24 and pipe is into the spray pipe l8. Thepressure of the water supply and the size of the pipes is such that thewater spray coming from spray pipe I8 is suflicient to cause thecondenser coil 5 to function as an atmospheric condenser.

The pressure operated valve 22 and the electrically operated valve 23are caused to operate by an increase in pressure in the condenser coilabove a predetermined level and preferably the pressure operated valveshould be set so as to open at the desired operating pressure of thecondenser while the electrically operated valve is set so as to openwhen the pressure approaches the pressure at which the high pressurecutout (not shown) of the refrigerating system shuts down thecompressor. Thus as a specific example where my invention is used inconnection with a refrigerating system employing ammonia as therefrigerant the pressure operated valve starts to open when the pressureof the refrigerant reaches 185 pounds and the electrically operatedvalve opens when the pressure reaches 225 pounds.

The pressure operated valve is provided with inlet and outlet chambers26 and 21 respectively between which is disposed the valve 28 whichseats against the valve seat 29. A valve stem 3| extends upwardly fromthe valve 28 and is connected at its upper end to a diaphragm 32. Tonormally hold the valve in closed position a spring 34 is disposedaround the stem between the diaphragm 32 and the transverse member 35. Acap 36 is connected overthe top of the diaphragm 32 so as to provide apressure chamber 31 connected by conduits 38 and 39 to a stem 40communicating with the interior of the condenser coil at the firstreturn bend. In this way the pressure in chamber 31 varies with thepressure of the refrigerant. As stated above when ammonia is used as therefrigerant, the tension of the spring 34 is such as to cause valve 28to open when the pressure of the refrigerant rises above approximately185 pounds. It will be appreciated that the amount that the valve opensis proportional to the pressure of the refrigerant, thus the higher thepressure the greater the valve opening and correspondingly the lower thepressure the smaller the valve opening.

The electrically operated valve 23 consists of inlet and outlet chambers4| and 42 respectively between which is disposed the valve 43 seatingagainst valve seat 44. It will be seen that the valve 43 seatsoppositely to valve 28. thus valve 28 is closed when in its uppermostposition and valve 43 is closed when in its lowermost position.Extending upwardly from valve 43 is valve stem 45, the upper end ofwhich forms an armature for solenoid 46. The valve is normally held inclosed position by means of a coil spring 41 disposed around the valvestem between collar 48 and supporting bracket 49. When the solenoid 46is energized it raises the valve stem and valve 43 upwardly to openposition. One end of the solenoid winding is connected by lead 50 to oneside of the source of current supply and the other end of the winding isconneotedby lead 5! to pressure actuated switch 52 which is alsoconnected by lead 53 to the other side of the source of current supply.The pressure actuated switch 52 is of conventional construction and isconnected by means of conduit 54 to conduit 39.

The pressure actuated switch 52 is normally open but when the pressureof the refrigerant approaches the critical pressure at which the highpressure cutout shuts down the compression the switch is operated so asto close the circuit of solenoid 46 with the result that valve 23 iscaused to open. When switch 52 is operated to close the circuit thecircuit remains closed regardless of any drop in pressure of therefrigerant until it has been manually opened by means of the manualreset button 55.

In the normal operation of a refrigerating condenser embodying myinvention in which ammonia is used as the refrigerant valve 22 ispreferably adjusted to open at 185 pounds pressure and pressure operatedswitch 52 is adjusted to operate at 225 pounds pressure so as to causevalve 23 to open. When the pump [2 and fan i are functioning properlythe condenser will operate as a shower, evaporator, or econornizercondenser and both of the valves 22 and 23 will normally be closed. Whenthe system is operating in this manner manually by-pass valve 25 shouldlikewise be closed. In the event that either the pump or fan cease tofunction properly the pressure in the condenser will commence to rise.As it rises above 185 degrees valve 22 will be caused to open, theopening in the valve being proportional to the pressure. However, theauxiliary spray pipe l8 will not operate as yet due to the fact thatelectrically operated valve 23 does not open until the pressure of therefrigerant reaches 225 pounds. When the pressure of the refrigerantdoes reach 225 pounds, pressure actuated switch 52 closes the circuit ofsolenoid 46 causing valve 23 to open. Water will then flow throughsupply pipe [4 and pipe 2|, 20 and I9 into spray pipe I8 and sufficientwater will be sprayed by the spray pipe l8 on the condenser coil 5 tocause the system to operate as an atmospheric condenser. a

Due to the large quantity of water sprayed by spray pipe 48 downwardlyover the coil 5 into drip pan 8, all of the water cannot be recirculatedby pump 12 and'this will pass through overflow or drainpipe I1. When thedefect in the pump or fan has been corrected electrically operated valve23 can be shut off by means of the manual reset button 55 on the switch52 and the system can once again function as a shower, evaporator, oreconomizer condenser. I

It will be appreciated that even where pump or fan failure has notcaused the pressure to rise sufficiently to operate the valves 22 and 23I can cause the system to operate as an atmospheric condenser by openingmanually controlled valve In certain types of systems as where a fusibleplug is employed in the condenser coil I prefer to operate the auxiliaryspray system by means of variations in the temperature of therefrigerant, preferably in the condensing zone of the condenser coil. Anapparatus of this character is illustrated in Figs. 2 and 3 of thedrawings which is similar in all respects to the first form of myinvention with the exception that a fusible plug 51 is disposed in thecondensing zone of the condenser coil 5 and the pressure actuated switchand pressure operated valve are connected to a thermostatic bulb ratherthan communicating directly with the refrigerant. Fusible plug 51 is of"conventional construction and is adapted to fuse and release therefrigerant when the temperature in the condensing zone passes above acritical point. Refrigerating systems employ sulphur dioxide, freon, andsimilar refrigerants sometimes employ fusible plugs of this character assafety devices.

In this form of my invention the pressure perated valve 22 and thepressure operated switch 52 are connected by the pipes oft-conduits 38and 54 respectively to a conduit 58 which in turn is connected to athermostatic bulb 59 of conventional construction positioned in thecondensing zone of the condenser coil as shown most clearly in Fig. 3. Apreferred type of structure is shown in the drawings and comprises afitting 60 threaded in the lowest return bend of the condenser coil andthrough which the conduit 58 projects. The fitting is providedwith anenlarged socket in which packing BI is disposed, the packing being heldin position by means of the threaded plug 62.

The thermostatic bulb 59 is a gas-filled bulb I and upon an increase inthe temperature of the refrigerant in the condensing zone there is acorresponding increase in the temperature and pressure of the gas in thethermostatic bulb. The increase in pressure is transmitted through theconduits 58 and 38 to pressure operated valve 22 and through theconduits 5B and 55 to the pressure operated switch 52. The parts are soad: justed so as to cause the operation of the switch 52 when thetemperature in the condensing zone rises to a point within 25 degreesFahrenheit of the temperature at which the fusible plug 51 fuses whilethe pressureactuated valve is adjusted so as to open when thetemperature in the condensing zone rises above the desired operatingtemperature. Thus where freon, sulphur dioxide and the like are employedthe valve is adjusted so as to open when the temperature rises above 90degrees Fahrenheit.

In .the normal operation 'of the condenser shown in Figs. 2 and 3 itoperates as an evaporator condenser. Thus the water is sprayed on thecoil from spray pipe 6 and the unevaporated portion thereof is receivedin the drip pan 8.

' The blower or fan 1 directs a current of air over and through thewater spray and over the coil causing rapid evaporation of a smallquantity of water, cooling the remainder of the water in the coil. Theunevaporated water that is received in the drip pan 8 is recirculatedthrough conduit l I by means of pump l2 and is again sprayed on thecoil. In the event of failure of either the pump or fan the condenserceases to function properly with the result that the temperature in thecondenser rises. When the temperature in the condensing zone rises abovethe desired operating temperature which, as stated above, is 90 degreesin the case of freon, sulphur dioxide or the like pressure operatedvalve 22 begins to open due to the increased pressure in thermobulb 59resulting from the rise in temperature. However, water. cannot circulatefrom supply pipe H through conduits 2i, and 19 due to the fact thatvalve 23 remains closed until the temperature rises to within degrees ofthe fusing temperature of the plug 51. When this point is reachedpressure actuated switch 52 is operated closing the circuit of thesolenoid winding 46 with the result that valve 23 is open permitting thewater from the supply pipe to flow through conduits 2|, 20 and I9 intothe atmospheric spray pipe l8. Suflicient water is then sprayed upon thecoil 5 to cause it to function as an atmospheric condenser. The surpluswater that is received in drip pan 8 passes outwardly through drain pipe11. After switch 52 has been operated to close the circuit of thesolenoid it remains open until manually reset by means of the resetbutton 55. Since the pressure operated valve 22 is adjusted so as toopen when the temperature in the condensing zone rises above 90 degreesthe system will.operate to maintain the temperature at approximatelythis level. 'When the evaporator condenser system has been repaired soas to again operate the atmospheric system may be shut off by means ofmanually reset button 55 on the switch 52; It will be appreciated thatthe atmospheric system is then in a position to operate again when, dueto failure of the evaporator system, the temperature in the condensingzone approaches within 25 degrees of the fusing point of the plug 51. Inthe modified form of my invention I also provide the conduit 24 andvalve 25 which maybe manually operated so as to convert the system tofunction as an atmospheric condenser.

From the foregoing description of my invention it will be appreciatedthat I have provided an improved condenser which may function both as anevaporator condenser or as an atmospheric condenser. It will also beappreciated that in normal operation the condenser operates economicallyas an evaporator type condenser but that upon failure of the pump or'fan the systemis automatically converted so as to function as anatmospheric condenser. While in the accompanying drawings I haveillustrated two specific embodiments of my invention it is'to beunderstood-that modifications may be made in the particular mechanicalor physical embodimerits of my invention without departing from theinvention as set forth in the accompanying claims.

I claim:

1. In a refrigerating condenser a condenser coil; evaporator type ofcooling means for cooling the coil comprising means for spraying wateron the coil, a fan for directing a current of air over the coil so as toevaporate a portion of the water, a drip pan positioned beneath the coilfor receiving the unevaporated portion of the water, and a pump forrecirculating the unevaporated portion of the water from the drip pan tothe spray means; and auxiliary cooling means for cooling the coilcomprising means for spraying sufiicient additional water on the coil tocause it to operate as an atmospheric condenser, a first valve forcontrolling said last-named means operatively connected to the coil soas to open when the physical condition of the refrigerant varies apredetermined amount from the normal physical condition of therefrigerant in the condenser coil and a second valve controlling saidlastnamed means and operatively connected to the coil so as to open whenthe physical condition of the refrigerant varies a predetermined greateramount, said predetermined greater variation being clearly beyond theconditions encountered when the condenser coil is functioning properlywhereby the auxiliary cooling means is caused to operate only upon thefailure of the evaporator cooling means, said second valve remainingopen even after the physical condition of the refrigerant returns tonormal While the setting of the first valve varies proportionally tovariations in the physical condition of the refrigerant so that the flowof water in the auxiliary cooling means is proportional to variations inthe physical condition of the refrigerant.

2. In a refrigerating condenser a condenser coil; evaporator type ofcooling means for cooling the coil comprising means for spraying wateron the coil, a fan for directing a current of air over the coil so as toevaporate a portion of the water, a drip pan positioned beneath the coilfor receiving the unevaporated portion of the Water, and a pump forrecirculating the unevaporated portion of the water from the drip pan tothe spray means; and auxiliary cooling means for cooling the coilcomprising means for spraying sufficient additional Water on the coil tocause it to operate as an atmospheric condenser, a first valve forcontrolling said last-named means operatively connected. to the coil soas to open when the pressure of the refrigerant rises above the normaloperating pressure of the condenser and a second valve controlling saidlast-named means and operatively connected to the coil so as to openwhen the pressure of the refrigerant rises above a predetermined higherpressure, said predetermined higher pressure being clearly abovepressures encountered in the cooling coil when the evaporator coolingmeans is functioning properly whereby the auxiliary cooling means iscaused to operate only upon the failure of the evaporating coolingmeans, said second valve remaining open even after the pressure of therefrigerant returns to normal while the setting of the first valvevaries in proportion to increases in the pressure of the refrigerant inthe condenser coil above normal pressure so that the fiow of the Waterin the auxiliary cooling means is proportional to the pressure of therefrigerant in the condenser coil.

3. In a refrigerating condenser a condenser coil; evaporator type ofcooling means for cooling the coil comprising means for spraying Wateron the coil, a fan for directing a current of air over the coil so as toevaporate a portion of the water, a drip pan positioned beneath the coilfor reeciving the unevaporated portion of the water, and a pump forrecirculating the unevaporated portion of the water from the drip pan tothe spray means; and auxiliary cooling means for cooling the coilcomprising means for spraying suflicient additional water on the coil tocause it to operate as an atmospheric condenser, a first valvecontrolling said auxiliary cooling means and operatively connected tothe condensing zone of the coil so as to open when the temperature ofthe refrigerant rises above the normal operating temperature and asecond valve controlling said last-named means and operatively connectedto the condensing zone of the coil so as to open when the temperaturerises above a predetermined higher temperature, said predeterminedhigher temperature being clearly above temperatures encountered in thecooling coil when the evaporator cooling means is functioning properlywhereby the auxiliary cooling means is caused to operate only upon thefailure of the evaporating cooling means, said second valve remainingopen even after the temperature of the refrigerant returns to normalwhile the setting of the first valve varies in proportion to increasesin the temperature of the refrigerant in the condenser coil above normaltemperature so that the flow of the water in tho auxiliary cooling meansis proportional to the temperature of the refrigerant in the condensercoil.

THOMAS S. WETTER.

